So it's the 21st century, and our collective knowledge in fields such as medicine and hygiene is better than at any other time in our past. If you have some medical problem, chances are we've developed a pretty good treatment for it that's better than it was 25 years ago, and 25 years before that. Just about everything anyone can think of has been tried and tested as a treatment for that condition. Why then do some Westerners shun the results of what we've been able to learn, and instead seek out folk remedies notable only for their roots in pre-scientific knowledge? Nowhere is this trend more aptly illustrated than in the latest fad, oil pulling.

Oil pulling is an alternative therapy that involves putting vegetable oil in your mouth, swishing it around for a few minutes, then spitting it out. There are many different variations. Some say you should do it for about 3 minutes; some say you should do it for a full 20 minutes. Some say you should gargle it; some say you should swish it around; some say you should fill your entire mouth cavity completely and just hold it. The types of oil to be used also do not seem to adhere to any particular standard: some say that any store-bought oil is equally useful; some specify that coconut oil should be used; some say sesame oil, sunflower oil, or even the oil produced by separating butter, called ghee in India.

For all the many variations of how oil pulling is to be done, there are just as many conflicting beliefs about what it is supposed to do for you. Most often found is the claim that it cleans and protects your teeth from plaque and bacteria, but just as common is the idea that it "pulls" toxins out of your body (thus the name oil pulling). Like all alternative detoxification claims, there is no accepted description of what these alleged "toxins" are. An article on Food Matters, an anti-pharmaceutical activism website based on the 2008 film of the same name, lists the following as other "possible benefits of oil pulling for overall health":

Migraine headache relief Correcting hormone imbalances Reducing inflammation of arthritis May help with gastro-enteritis Aids in the reduction of eczema May reduce symptoms of bronchitis Helps support normal kidney function May help reduce sinus congestion Some people report improved vision Helps reduce insomnia Reduced hangover after alcohol consumption Aids in reducing pain Reduces the symptoms of allergies Helps detoxify the body of harmful metals and organisms

Taken by itself, any one of these is likely to raise your eyebrows: How, the 21st century mind might ask, could swishing a non-specific type of oil in your mouth using non-specific technique address any or all of these conditions? Is human biology really so simple and its health really so easily manipulated? How could someone be convinced by such a claim?

The answer to that question should come as no surprise to regular Skeptoid listeners. We turn to our list of logical fallacies, and look up the Appeal to Antiquity: the invalid logic which states that an idea is old, therefore it's valid. The antiquity in this case, as presented by nearly every book and website that promotes oil pulling, is ayurveda, traditional medicine from India. As discussed by Skeptoid blogger Mike Rothschild, oil pulling is said to originate in the Charaka Samhita, one of the two principal texts upon which ayurveda is founded. According to the 2002 translation by Gabriel Van Loon, "oil gargling":

Provides strength in jaws and voice, development of face, maximum taste and relish in food. One does not suffer from dryness of throat, lipcracking, tooth cavities, pain in teeth, over-sensitivity of teeth on taking sour taste; teeth become firm-rooted, able to chew even the hardest food items.

This gargling is to be performed with ghee, the oil from separated butter.

And therein lies the problem with the modern Western attribution of oil pulling to ayuerveda. It's with butter oil, not vegetable oil; it's gargled, not swished in the mouth for 20 minutes; and the Charaka Samhita makes no mention whatsoever of anything from the modern advocates' long list of medical conditions that it supposedly cures — except that the ancient Indians believed it was good for the teeth. So the question to ask is if oil pulling's foundation is ancient wisdom, why does the version that's so popular right now differ so comprehensively from the ancient version? The rational assumption is that some research or testing must have improved the ancient version of oil pulling knowledge.

Except that it hasn't. A survey of the scientific literature reveals that almost no serious studies have even been performed at all, by anyone — except one man, an Indian doctor of ayurveda named S. Asokan. Virtually all information on the Internet about oil pulling cites one of a handful of studies by Asokan and some of his colleagues. Asokan, working at ayurvedic institutions inside India and publishing only in Indian journals, concluded that oil pulling was marginally better than chlorhexidine, an ingredient in modern mouthwash, at killing bacteria. But when Dr. Steven Novella at the Science-Based Medicine blog re-analyzed the data in one of Asokan's studies, he found the data indicated the opposite, that chlorhexidine was actually marginally better than oil pulling.

Regardless there is certainly no strong science-based conclusion either way; and not even any serious pro-oil pulling researchers have published anything supporting the technique for any purposes other than as an oral bactericide. If you're hoping it will cure malignant tumors, paralysis, or arthritis, not even its major proponents have gone that far.

But what if you want to learn more? What if you want to find out for yourself who has been promoting oil pulling, and as a treatment for what medical conditions?

There's one simple and interesting tool that should be found in every skeptic's toolbox, and that's Google Trends. This online tool shows you the frequency of Internet search terms over time. When a subject is in people's minds, they do Internet searches for it. Studying these trends can show us when a subject became popular, and this sometimes allows us to correlate certain events or publications with the popularity of ideas. Oil pulling, as a search term, was essentially nonexistent until late 2006, when it received a slight bump that put it on the map, though at a very low level, until 2012. It grew slowly but unevenly through 2013, until February-March 2014 when it exploded. Oil pulling was officially a huge fad, very suddenly.

How? Why? Was some new research published? Not quite; something happened with a far deeper reach into the public psyche. On February 5, 2014 (notice the alignment with the explosion in search term popularity), oil pulling was featured on television on (you guessed it) the Dr. Oz Show. Yes, that very same Dr. Oz, the world's most visible promoter of alternative medicine and fanatical opponent of science-based medicine. Dr. Oz's ayurvedic blogger, Kulreet Chaudhary, had blogged about it on and off for a few years, but it wasn't until he featured her on his TV show to promote oil pulling as a way to "detoxify" the mouth that it really went viral.

A bump in Google Trends in 2013 coincided with a Huffington Post article in the Beauty and Style section, which was cited as part of the growth by Rothschild; and that article also cited the writings of naturopath Bruce Fife in his 2008 book Oil Pulling Therapy: Detoxifying and Healing the Body Through Oral Cleansing. But perhaps the most interesting comment I've seen came from online author Lisa Barger, and again, notice how well the timing she mentions matches up to the Google Trends' 2006 appearance of oil pulling:

In 2006 I began to run across a number of forum posts all asking the same question: "Has anyone tried oil pulling?" The names of the persons asking the question was usually different but the way the question was phrased — and the extensive explanation the asker went on to give after asking his or her question — often seem just a tad too familiar. As I began again to investigate, I came to suspect that many of those questions were being asked to "seed" interest in some new websites that promoted a completely bogus "therapy" called oil pulling. To this day I still believe it was an attempt at viral marketing — and I said so.

I've seen this done before to promote upcoming books or documentaries, something of a ham-handed effort to generate grassroots interest in an idea. Barger's suspicion strikes me as perfectly likely, though not reliably evidenced. She did make one other well-stated point having to do with the claim that oil pulling somehow pulls these unidentified "toxins" out of your body:

Your blood vessels don't just leak toxins. If chemicals could just leak through the walls of your arteries and veins we'd have no need for oil pulling, would we? We could just rinse our mouths briefly several times a day with plain water and be done with it.

Most discussions of oil pulling that are not promotions to buy some expensive specialized coconut oil end with a similar conclusion, and it's the same one I'll agree with here. Oil pulling is unlikely to hurt you. Unless you do fall for some special advertised overpriced oil, it's probably not even going to cost you any money to try. However, it's equally unlikely to help you. If you prefer to spend 20 minutes reducing your oral bacteria every day instead of brushing your teeth or swishing some mouthwash, then knock yourself out. If you are attracted to the idea of traditional Indian medicine, then boil up some butter to skim off the oil and gargle with it once a day; that's not going to hurt you either. But a better lesson to learn is the genesis of an Internet myth. Why somebody decided to re-interpret the Charaka Samhita and promote oil pulling as a medical miracle escapes me, but it successfully wormed its way through the bowels of online forums for six years and then happened to strike the mother lode of Dr. Oz sensationalism. Let's hope that whoever did this found it to be worthwhile, because it really hasn't been for anyone else.